While traveling through Gotham in Batman: Arkham Knight, you can listen in on the radio conversations of criminals and militia-members. One particular set of dialogue caught my attention; it featured a criminal's complaint about both Batman and "that other freak in Metropolis." This, at least in my opinion, clearly confirms the existence of Superman in the Batman Arkham video-game universe, especially when taken alongside the presence of both the Lexcorp building and Luthor's quasi-threatening voicemail to Bruce Wayne in-game. Will Superman (or Luthor) make a cameo appearance in the future Batman titles we all know (or at least desperately hope) are coming? Will he get his own standalone game? Some may say I'm reaching, but considering Rocksteady's penchant for innocuous-yet-highly-relevant Easter Eggs, we may soon be hearing an announcement for the Superman game fans have all been waiting for!